The widespread adoption of tables, released with HTML 2.0 and enhanced with HTML 3.2, radically
changed layout control. Designers gained the capability to align objects and text??”but a lot of graphical eye
candy was still left to graphic files strategically located within the tables. The harder designers worked at
precisely laying out their Web pages, the more they had to resort to workarounds such as nested tables and
1-pixel-wide GIFs used as spacers. To relieve the woes of Web designers everywhere, the W3C included a
feature within the new Cascading Style Sheets specifications that allows for absolute positioning of an element
upon a page. Absolute positioning enables an element, such as an image or block of text, to be placed
anywhere on the Web page. Browser support for Cascading Style Sheets-Positioning specification began
with fourth-generation browsers and has grown steadily ever since.
The addition of the third dimension, depth, truly turned the positioning specs into AP elements. Now
objects can be positioned side by side, and they have a z-index property as well. The z-index gets its name
from the practice in geometry of describing three-dimensional space with x, y, and z coordinates; z-index is
also called the stacking order because objects can be stacked upon one another.
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